net: atlantic: QoS implementation: multi-TC support

This patch adds multi-TC support.

PTP is automatically disabled when the user enables more than 2 TCs,
otherwise traffic on TC2 won't quite work, because it's reserved for PTP.

Signed-off-by: Dmitry Bezrukov <dbezrukov@marvell.com>
Co-developed-by: Dmitry Bogdanov <dbogdanov@marvell.com>
Signed-off-by: Dmitry Bogdanov <dbogdanov@marvell.com>
Co-developed-by: Mark Starovoytov <mstarovoitov@marvell.com>
Signed-off-by: Mark Starovoytov <mstarovoitov@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>